ABSTRACT We request to continue our NIA cohort study (?LitCog?; R01AG030611). LitCog studies the confluence of increased medical morbidity resulting in complex patient self-management (SM) roles, and cognitive decline, which may affect older patients? health literacy (HL) skills and chronic illness self-care. Functionally independent, ?cognitively normal? adults ages 55-74 (N=900) were recruited from community primary care practices in Chicago. Participants have completed comprehensive cognitive, psychological, social, behavioral, and functional health assessments every 3 years (4 interviews; 2008-2018). The sample is diverse by race, socioeconomic status and medical morbidity; uncommon among cognitive aging studies. A 1st renewal award (LitCog II) examined changes in cognition, HL and SM skills over 6 years and their associations with physical and mental health. We found cognitive function to be strongly associated with HL; both decline together over time. Cognitive function and HL also determine older adults? SM skills; all predict functional health status and its decline. A 2nd renewal (LitCog III) has allowed us to capture new health behaviors, chronic disease outcomes, and healthcare use from medical, pharmacy records a decade post-baseline. Cognitive function, HL and SM skills impact all of these outcomes. LitCog III is almost complete; 774 of 900 (86%) subjects are alive and available for further study. We now propose to conduct follow-up assessments 12 and 15 years post-baseline (LitCog IV). With 6 interviews over 15 years, specific trajectories of decline in cognition, HL, SM skills and health status can be closely studied. The prevalence of and adjustment to increasing morbidity, disability, cognitive impairment (including Alzheimer?s Disease & Related Dementias (ADRD)) allow for new outcomes for investigation. Mortality data will also now be available with extended follow-up. Our primary aim is to 1) evaluate trajectories in cognitive function, HL and SM skills over 15 years among older adults, and their associations with health outcomes. LitCog is an exceptionally unique cognitive aging cohort study as it is framed in the context of health services research. Our goal has been to inform health system strategies for effectively managing older patients by understanding how cognition changes and influences HL and SM skills necessary for achieving optimal health. Modifiable factors that may mediate/moderate associations are also explored as potential intervention targets. The involvement and roles of caregivers has specifically emerged as an important social determinant of patients? health. An administrative ADRD supplement (LitCog IIIA) has expanded our inquiry by including interviews with caregivers (informal or paid) involved in supporting the care of 60% of participants. In LitCog IV, we will create a parallel caregiver cohort, with the secondary aims to 2) investigate associations between the presence of an involved caregiver with treatment adherence, chronic disease outcomes, and functional health status among older adults; 3) identify factors influencing associations between caregiver involvement and patient outcomes.